Advantages or dis Advantages for a 4mm arrow

[roadsterguy]

Been away from bow hunting for a few years and looking to pickup a lighter draw weight bow and have 1 1/2 doz. 4mm FMJ, only used for turkeys which worked fine, bought them maybe 8yrs ago but thinking of keeping them. Any good or bad results using a 4mm arrow?

 

[Bump79]

Good - less wind drift and maybe some penetration. Marginal there IMHO.

Bad - Components aren't as strong. So you need to invest in better broadheads and collars if deep six. If using a half out or similar - they likely need upgraded as well. The half outs bend super easy.

 

[Mighty Mouse]

The 4mm juice ain’t worth the squeeze IMO. The only 4mm insert I would trust is a Deep Six HIT (hidden insert), which severely limits your broadhead choices to only those offered with Deep Six (6-40) threads. Standard diameter (6.5mm) arrows with good old-fashioned full-insertion flanged inserts are my go-to recommendation.

 

[roadsterguy]

The 4mm juice ain’t worth the squeeze IMO. The only 4mm insert I would trust is a Deep Six HIT (hidden insert), which severely limits your broadhead choices to only those offered with Deep Six (6-40) threads. Standard diameter (6.5mm) arrows with good old-fashioned full-insertion flanged inserts are my go-to recommendation.

I need to verify but I believe it is the Deep Six HIT. I bought extra components when I bought the arrows, I'll have to check. Thanks for the info

 

[Blockcaver]

I really like the old discontinued Easton 4mm Carbon Injexions. 330 spine in my case. Been using them since 2013 and have enough to last me quite a few more years. Killed a pile of animals using them including a real nice Mt Caribou and good Black Bear this year.

I've shot Elk, several Caribou, Stone and Dall rams, Polar Bear, Brown Bear, Musk Ox and a couple Moose with them besides Deer and a lot of Black Bears..

The shafts as well as the components I use have proven very durable. I install the provided D-6 22 grain weight stainless steel insert to stock depth using Easton provided epoxy. That D-6 insert is just for reinforcing and a bit of FOC. I do NOT like D-6 components as they are thin and weak vs regular components....so use Firenock outserts so I can utilize regular 8-32 threaded broadheads and field points. With a 4" wrap, regular Easton nock, 3 helical Blazers and a 100 grain broadhead my arrows come in at about 471 grains for my 29-5/16" draw length 65# bow.

Good luck to you and your 4mm shafts. I like 'em!

 

[tdoublev]

The main advantage with 4mm is less wind drift, but unless you are shooting from a covered spot (with no wind) into an open area (with wind), you won’t get this benefit because the wind will be blowing your entire bow. At that point, you’re just trying to keep the sight on target. The big down side as already said is the weakness of components. I definitely didn’t appreciate how much they bend until after I started shooting them. They will bend shooting into the wrong spots on a 3D target or even hitting another arrow. Doesn’t take a miss for this to happen.

The main reason I had chosen 4mm to start was because they were lighter than the larger diameter arrows (I have a short draw length so I need the speed) while still maintaining durability of the tougher arrows like a VAP TKO. However, since the components bend easily this became a moot point because they failed way before the arrow shaft did. And, I think with today’s arrows the regular diameter carbon arrows are plenty durable and still light enough so I don’t need 4mm for weight purposes or FMJ/VAP for durable arrows. You may feel differently if you think you’ll miss a lot, but for me normal carbon has been fine and with the cost savings it’s not a big deal if one would crack (which hasn’t happened yet from target shooting).

 

[jonnyviceroy]

The larger diameter arrows are more forgiving tuning wise. I’ve always noticed 4mm to be less forgiving and harder to tune.
Because of the larger area for displacement larger diameter arrows tend to give you a wider sweet spot for acceptable nock travel and rest position.
Definitely can all be mitigated but is a small factor I’ve noticed.

 

[Blockcaver]

The main advantage with 4mm is less wind drift, but unless you are shooting from a covered spot (with no wind) into an open area (with wind), you won’t get this benefit because the wind will be blowing your entire bow. At that point, you’re just trying to keep the sight on target.

In the wind I try to take off my quiver and shoot from my knees if the terrain allows. Much steadier that way than standing up with the quiver on.

 

[Beendare]

The 4mm juice ain’t worth the squeeze IMO. The only 4mm insert I would trust is a Deep Six HIT (hidden insert), which severely limits your broadhead choices to only those offered with Deep Six (6-40) threads. Standard diameter (6.5mm) arrows with good old-fashioned full-insertion flanged inserts are my go-to recommendation.

^Agreed. 4mm is a solution that creates more problems.

The 4mm shafts themselves are fine though a little bit harder to fletch. The only advantage over 5mm in wind is if you are shooting very long 80y plus shots.

4mm creates problems with getting your inserts and BH's perfect since they don't fit inside....where there is none of that with 5mm and std shafts if you mill the ends square.

 

[S.Clancy]

The 4mm juice ain’t worth the squeeze IMO. The only 4mm insert I would trust is a Deep Six HIT (hidden insert), which severely limits your broadhead choices to only those offered with Deep Six (6-40) threads. Standard diameter (6.5mm) arrows with good old-fashioned full-insertion flanged inserts are my go-to recommendation.

This guy has it. 4mm are in no way worth the aggravation or the $$$. There are tons of cheap 6mm arrows that are great. Or 5mm, but they are more expensive than the 6mm.

 

[Pramo]

I've had 4mm an used them off and on, they are great but they lose spine after lots of use. I've had 4mm axis that just started shooting bad, figured my bow changed and it was never the bow. Trusty 5mm axis match grade would fly perfect.

4mm just to finicky to keep messing with, I did hit inserts and iron will collars they were great till flight started going down hill. 5mm is a good enough balance and cheaper in the long run

 

[2Stamp]

Only reason I'm using 4mm last yr/ this year is because I was given a couple dozen by my arrow reps. I like 5mm better.

 

[ganngus]

I've shot 4mm exclusively since 2016. The main downside I see is the GPI on heavier spines. I'd love to try the Easton X10s Parallel Pros, but for 250 spine its 10.8GPI (whereas 300 is 9.5). Accordingly, I am sticking to Black Eagle X-Impacts at 9.5GPI in 250 spine. Unless Iron Will Outfitters goes out of business or stops making 4mm components, the lack of components doesn't mean anything to me personally.

From a physics standpoint, 4mm fly better than a 5mm. I am aware of no scientific studies that show that 5mm or 6mm arrows fly better/penetrate deeper than 4mm. Conversely, Western Hunters' arrow study opined as follows:

Did 4mm arrows have an advantage over larger diameter shafts?
Yes, they did! During the testing, we used our baseline arrow build to iterate on arrow diameter. We tested 4mm shafts, 5mm, and 6.5mm. According to the ballistics testing, 4mm arrows had a drag coefficient that was 10% less than 5mm arrows. This may not sound significant, but bowhunting is a game of inches, and that decrease in drag can lead to multiple inches less drop and less wind drift at extended range. A couple of inches is the difference between a wound and a solid kill simply by choosing a slimmer shaft.

 

[roosiebull]

Been away from bow hunting for a few years and looking to pickup a lighter draw weight bow and have 1 1/2 doz. 4mm FMJ, only used for turkeys which worked fine, bought them maybe 8yrs ago but thinking of keeping them. Any good or bad results using a 4mm arrow?

I’m shooting 4mm currently and it makes me feel dumb that I had to revisit 4mm, the big con is components, unless you go all glue in, it’s a compromise, without enough in return to even measure in the real world, I have almost 2doz and after season I’m scrapping them and just use them for sage rats in the spring

5mm is my favorite balance

I could rant about fmj’s too

I won’t ever buy 4mm again unless there is a big component breakthrough, but I don’t see that. 4mm is too big of a compromise imo

 

[Billy Goat]

Did 4mm arrows have an advantage over larger diameter shafts?
Yes, they did! During the testing, we used our baseline arrow build to iterate on arrow diameter. We tested 4mm shafts, 5mm, and 6.5mm. According to the ballistics testing, 4mm arrows had a drag coefficient that was 10% less than 5mm arrows. This may not sound significant, but bowhunting is a game of inches, and that decrease in drag can lead to multiple inches less drop and less wind drift at extended range. A couple of inches is the difference between a wound and a solid kill simply by choosing a slimmer shaft.

I'm ignorant to this study, so forgive me.

But was it done with broadheads (fixed or mech) and appropriate sized hunting fletching?

At 10% improvement, I feel like it might have, im just curious.

The link seems to just be showing arrows, not the study.

 

[JNDEER]

Other information in here as well, but they touch on the tested benefit of a 4mm arrow.

Arrow Ballistics Study | Precision Cut Archery

The most precise sight tapes, cut charts, and ballistics data available, meticulously tailored to your unique setup and style.

www.precisioncutarchery.com

Personally I shoot 5mm as others have stated the component and BH selections are limited.

 

[roadsterguy]

Other information in here as well, but they touch on the tested benefit of a 4mm arrow.

Arrow Ballistics Study | Precision Cut Archery

The most precise sight tapes, cut charts, and ballistics data available, meticulously tailored to your unique setup and style.

www.precisioncutarchery.com

Personally I shoot 5mm as others have stated the component and BH selections are limited.

Yes when I bought the arrows it was all deep 6 inserts field points and BH. I did shoot a couple turkeys but no big game, I door have a very limited amount of 5mm but plenty of BH. Got to shooting Blue grouse which can be hard on arrows and BH. But fun and tasty. Thanks for the input.

 

[Billy Goat]

Other information in here as well, but they touch on the tested benefit of a 4mm arrow.

Arrow Ballistics Study | Precision Cut Archery

The most precise sight tapes, cut charts, and ballistics data available, meticulously tailored to your unique setup and style.

www.precisioncutarchery.com

Personally I shoot 5mm as others have stated the component and BH selections are limited.

The raw data I'm seeing they have is all with 5mm shafts, testing broadheads and fletching.



They say 4mm had 10% less drag coefficient, but I'm not seeing data supporting once testing broadheads. Maybe I'm missing it.


There's a fair advantage on arrow diameter in the wind with small vanes and a broadhead. I think once you have a .45" or taller fletch and even most any of the mechanical heads available, the difference in wind drift is almost moot.

 

[vmals]

Components are a pia. They bend, get stuck in bag targets, and the good ones are expensive but not bomb proof. I shoot rip tkos with 75 grain hits and my hunting arrows have 50gr hits with a 25 gr IW collar.

 

[ResearchinStuff]

I used to shoot 4mm, switched to 5mm and have seen improved accuracy and much more consistent tuning. In 4mm I would only use glue in points, the other front end systems are crap for 4mm.